#include "file.h"

#include <algorithm>
#include <string>
#include <unordered_set>

#include <libreichwein/stringhelper.h>

#include "env.h"

namespace fs = std::filesystem;
using namespace std::string_literals;

const fs::path YMakefile{"YMakefile"};

// type of file can be built from dependencies
bool is_buildable_by_extension(const fs::path& p) {
 fs::path ext{p.extension()};
 return ext.empty() || ext == ".o" || is_dynamic_lib(p) || is_dynamic_lib_link(p) || is_static_lib(p) ;
}

namespace {
 std::unordered_set<fs::path> compile_unit_source_types{".cpp", ".c", ".cc", ".S", ".rs"};
}

// type of file is source of compile unit (no included types like headers)
bool is_compile_unit_source_by_extension(const fs::path& p) {
 fs::path ext{p.extension()};
 return compile_unit_source_types.find(ext) != compile_unit_source_types.end();
}

bool is_executable_target(const std::filesystem::path& p)
{
 return p.extension().empty();
}

// e.g. libxyz.so.1.2.3 (the shorter versions are links to this one)
bool is_dynamic_lib(const std::filesystem::path& p)
{
 std::string name{p.filename()};
 return name.find(".so.") != name.npos && std::count(name.begin(), name.end(), '.') == 4;
}

// e.g. libxyz.so.1 libxyz.so
bool is_dynamic_lib_link(const std::filesystem::path& p)
{
 std::string name{p.filename()};
 return name.find(".so") != name.npos && std::count(name.begin(), name.end(), '.') < 4;
}

// in: libxyz.so.1.2.3
// out: libxyz.so.1
std::filesystem::path soname_shorter(const std::filesystem::path& p)
{
 std::string name{p.filename()};

 if (std::count(name.begin(), name.end(), '.') != 4) {
  throw std::runtime_error("Unexpected soname: "s + name + ", 4 dots expected.");
 }

 size_t pos{0};
 for (int i = 0; i < 3; ++i) {
  pos = name.find('.', pos);
  ++pos;
 }

 name = name.substr(0, pos - 1);

 fs::path result{p};
 result.replace_filename(name);
 return result;
}

// in: libxyz.so.1.2.3
// out: libxyz.so
std::filesystem::path soname_short(const std::filesystem::path& p)
{
 std::string name{p.filename()};

 if (std::count(name.begin(), name.end(), '.') != 4) {
  throw std::runtime_error("Unexpected soname: "s + name + ", 4 dots expected.");
 }

 size_t pos{0};
 for (int i = 0; i < 2; ++i) {
  pos = name.find('.', pos);
  ++pos;
 }

 name = name.substr(0, pos - 1);

 fs::path result{p};
 result.replace_filename(name);
 return result;
}

// e.g.
//  subdir1/libxyz.so.1.2.3 -> xyz
//  libabc.so -> abc
//  file1.so.1 -> file1
std::string dynamic_lib_name(const std::filesystem::path& p)
{
 std::string result {p.stem().string()};
 if (result.substr(0, 3) == "lib") {
  result = result.substr(3);
 }
 return result;
}

bool is_static_lib(const std::filesystem::path& p)
{
 return p.extension() == ".a";
}

std::filesystem::path simplified_path(const std::filesystem::path& p)
{
 if (p.string().substr(0, 2) == "./") {
  return p.string().substr(2);
 }
 return p;
}

bool is_executable_command(const std::string& file) {
 std::vector<std::string> paths {Reichwein::Stringhelper::split(env_value("PATH"), ":")};

 for (const auto& i: paths) {
  fs::path path{i + "/" + file};
  if (fs::exists(path) && (fs::status(path).permissions() & std::filesystem::perms::others_exec) != std::filesystem::perms::none) {
   return true;
  }
 }

 return false;
}

std::string find_executable(const std::vector<std::string>& list) {
 std::vector<std::string> paths {Reichwein::Stringhelper::split(env_value("PATH"), ":")};

 for (const auto& i: list) {
  for (const auto& j: paths) {
   fs::path path{j + "/" + i};
   if (fs::exists(path) && (fs::status(path).permissions() & std::filesystem::perms::others_exec) != std::filesystem::perms::none) {
    return i;
   }
  }
 }

 return {};
}